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Full-Text Articles in Physical Sciences and Mathematics

Modelling Strong Lenses From Wide-Field Ground-Based Observations In Kids And Gama, Shawn Knabel, Benne Holwerda, J Nightingale, T Treu, M Bilicki, S Brough, S Driver, L Finnerty, L Haberzettl, S Hegde, A M. Hopkins, K Kuijken, J Liske, A K. Pimblett, R C. Steele, A H. Wright Jan 2023

Modelling Strong Lenses From Wide-Field Ground-Based Observations In Kids And Gama, Shawn Knabel, Benne Holwerda, J Nightingale, T Treu, M Bilicki, S Brough, S Driver, L Finnerty, L Haberzettl, S Hegde, A M. Hopkins, K Kuijken, J Liske, A K. Pimblett, R C. Steele, A H. Wright

Faculty Scholarship

Despite the success of galaxy-scale strong gravitational lens studies with Hubble-quality imaging, a number of well-studied strong lenses remains small. As a result, robust comparisons of the lens models to theoretical predictions are difficult. This motivates our application of automated Bayesian lens modelling methods to observations from public data releases of overlapping large ground-based imaging and spectroscopic surveys: Kilo-Degree Survey (KiDS) and Galaxy and Mass Assembly (GAMA), respectively. We use the open-source lens modelling software PYAUTOLENS to perform our analysis. We demonstrate the feasibility of strong lens modelling with large-survey data at lower resolution as a complementary avenue to studies …


Individual Element Sensitivity For Stellar Evolutionary Isochrones, Guy Worthey, Xiang Shi, Tathagata Pal, Hyun-Chul Lee, Baitian Tang Jan 2022

Individual Element Sensitivity For Stellar Evolutionary Isochrones, Guy Worthey, Xiang Shi, Tathagata Pal, Hyun-Chul Lee, Baitian Tang

Physics and Astronomy Faculty Publications and Presentations

Stellar evolution calculations with variable abundance ratios were used to gauge the effects on temperatures, luminosities, and lifetimes in various phases. The individual elements C, N, O, Mg, Si, and Fe were included. Most of the effect relevant to integrated light models is contained in the temperature variable, as opposed to the time-scale or luminosity. We derive a recipe for including abundance-sensitive temperature effects that is applicable to existing isochrone grids. The resultant enhanced isochrones are incorporated into composite stellar population models and compared with galaxy data from the Sloan Digital Sky Survey. A severe oxygen–age degeneracy is apparent, 2–3 …


Updated Analysis Of An Unexpected Correlation Between Dark Matter And Galactic Ellipticity, D. M. Winters, Alexandre Deur, X. Zheng Jan 2022

Updated Analysis Of An Unexpected Correlation Between Dark Matter And Galactic Ellipticity, D. M. Winters, Alexandre Deur, X. Zheng

Physics Faculty Publications

We investigate a correlation between the dark matter content of elliptical galaxies and their ellipticity ϵ that was initially reported in 2014. We use new determinations of dark matter and ellipticities that are posterior to that time. Our data set consists of 237 elliptical galaxies passing a strict set of criteria that selects a homogeneous sample of typical elliptical galaxies. We find a relation between the mass-to-light ratio and ellipticity ϵ that is well fitted by M/L = (14.1 ± 5.4)ϵ, which agrees with the result reported in 2014. Our analysis includes 135 galaxies that were not in …


The Observable Supernova Rate In Galaxy–Galaxy Lensing Systems With The Tess Satellite, Benne Holwerda, S Knabel, R C. Steele, L Strolger, J Kielkopf, A Jacques, W Roemer Jun 2021

The Observable Supernova Rate In Galaxy–Galaxy Lensing Systems With The Tess Satellite, Benne Holwerda, S Knabel, R C. Steele, L Strolger, J Kielkopf, A Jacques, W Roemer

Faculty Scholarship

The Transiting Exoplanet Survey Satellite (TESS) is the latest observational effort to find exoplanets and map bright transient optical phenomena. Supernovae (SNe) are particularly interesting as cosmological standard candles for cosmological distance measures. The limiting magnitude of TESS strongly constrains SN detection to the very nearby Universe (m ∼ 19, z < 0.05). We explore the possibility that more distant SNe that are gravitationally lensed and magnified by a foreground galaxy can be detected by TESS, an opportunity to measure the time delay between light paths and constrain the Hubble constant independently. We estimate the rate of occurrence of such systems, assuming reasonable distributions of magnification, host dust attenuation, and redshift. There are approximately 16 Type Ia SNe (SNIa) and …


Chromodynamical Analysis Of Lenticular Galaxies Using Globular Clusters And Planetary Nebulae, Emilio Zanatta, Arianna Cortesi, Ana Chies-Santos, Duncan Forbes, Aaron Romanowsky, Adebusola Alabi, Lodovico Coccato, Claudia Mendes De Oliveira, Jean Brodie, Michael Merrifield Oct 2018

Chromodynamical Analysis Of Lenticular Galaxies Using Globular Clusters And Planetary Nebulae, Emilio Zanatta, Arianna Cortesi, Ana Chies-Santos, Duncan Forbes, Aaron Romanowsky, Adebusola Alabi, Lodovico Coccato, Claudia Mendes De Oliveira, Jean Brodie, Michael Merrifield

Faculty Publications

Recovering the origins of lenticular galaxies can shed light on the understanding of galaxy and compare them with the kinematics of planetary nebulae (PNe). The PNe and GC data come from the Planetary Nebulae Spectrograph and the SLUGGS Surveys. Through photometric spheroid-disc decomposition and PNe kinematics. we find the probability for a given GC to belong to either the spheroid or the disc of its host galaxy or be rejected from the model. We find that there is no correlation between the components that the GCs are likely to belong to and their colours. Particularly, for NGC 2768, we find …


The Sluggs Survey: The Inner Dark Matter Density Slope Of The Massive Elliptical Galaxy Ngc 1407, Asher Wasserman, Aaron Romanowsky, Jean Brodie, Pieter Van Dokkum, Charlie Conroy, Alexa Villaume, Duncan Forbes, Jay Strader, Adebusola Alabi, Sabine Bellstedt Aug 2018

The Sluggs Survey: The Inner Dark Matter Density Slope Of The Massive Elliptical Galaxy Ngc 1407, Asher Wasserman, Aaron Romanowsky, Jean Brodie, Pieter Van Dokkum, Charlie Conroy, Alexa Villaume, Duncan Forbes, Jay Strader, Adebusola Alabi, Sabine Bellstedt

Faculty Publications

We investigate the dark matter density profile of the massive elliptical galaxy, NGC 1407, by constructing spherically symmetric Jeans models of its field star and globular cluster systems. Two major challenges in such models are the degeneracy between the stellar mass and the dark matter halo profiles, and the degeneracy between the orbital anisotropy of the tracer population and the total mass causing the observed motions. We address the first issue by using new measurements of the mass-to-light ratio profile from stellar population constraints that include a radially varying initial mass function. To mitigate the mass–anisotropy degeneracy, we make use …


Shocks Or Photoionization: Direct Temperature Measurements Of The Low-Ionization Gas In Quiescent Galaxies, Renbin Yan Aug 2018

Shocks Or Photoionization: Direct Temperature Measurements Of The Low-Ionization Gas In Quiescent Galaxies, Renbin Yan

Physics and Astronomy Faculty Publications

The ionization mechanism of the low-ionization gas in quiescent red-sequence galaxies has been a long-standing puzzle. Direct temperature measurements would put strong constraints on this issue. We carefully selected a sample of quiescent red-sequence galaxies from Sloan Digital Sky Survey. We bin them into three bins with different [N II]/H α and [N II]/[O II] ratios, and we measure the temperature-sensitive [O III] λ4363, [N II] λ5755, [S II] λλ4068, 4076, and [O II] λλ7320, 7330 lines in the stacked spectra. The [S II] doublet ratios indicate the line-emitting gas is in the low-density regime (∼10–200 cm−3). We …


Globular Cluster Population Of The Hst Frontier Fields Galaxy J07173724+3744224, Nathan L. Carlson, Madina R. Sultanova, Sandanuwan P. Kalawila Vithanage, Wayne A. Barkhouse, Gihan L. Ipita Kaduwa Gamage, Cody M. Rude, Omar López-Cruz Jul 2018

Globular Cluster Population Of The Hst Frontier Fields Galaxy J07173724+3744224, Nathan L. Carlson, Madina R. Sultanova, Sandanuwan P. Kalawila Vithanage, Wayne A. Barkhouse, Gihan L. Ipita Kaduwa Gamage, Cody M. Rude, Omar López-Cruz

Physics Faculty Publications

We present the first measurement of the globular cluster (GC) population surrounding the elliptical galaxy J07173724+3744224 (⁠z" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: inherit; line-height: normal; font-family: inherit; vertical-align: baseline; display: inline; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; position: relative;">zz = 0.1546). This galaxy is located in the foreground in the field-of-view of the Hubble Space Telescope (HST) Frontier Fields observations of galaxy cluster MACS J0717.5+3745 (⁠z" role="presentation" style="box-sizing: border-box; margin: 0px; padding: 0px; border: 0px; font-variant: inherit; font-stretch: …


The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan Forbes, Aaron Romanowsky, Rhea-Silvia Remus, Adam Stevens, Jean Brodie, Adriano Poci, Richard Mcdermid, Adebusola Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya Jun 2018

The Sluggs Survey: A Comparison Of Total-Mass Profiles Of Early-Type Galaxies From Observations And Cosmological Simulations, To ∼4 Effective Radii, Sabine Bellstedt, Duncan Forbes, Aaron Romanowsky, Rhea-Silvia Remus, Adam Stevens, Jean Brodie, Adriano Poci, Richard Mcdermid, Adebusola Alabi, Leonie Chevalier, Caitlin Adams, Anna Ferré-Mateu, Asher Wasserman, Viraj Pandya

Faculty Publications

We apply the Jeans Anisotropic Multi-Gaussian Expansion dynamical modelling method to SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey data of early-type galaxies in the stellar mass range 1010 < M*/M⊙ < 1011.6 that cover a large radial range of 0.1–4.0 effective radii. We combine SLUGGS and ATLAS3D data sets to model the total-mass profiles of a sample of 21 fast-rotator galaxies, utilizing a hyperparameter method to combine the two independent data sets. The total-mass density profile slope values derived for these galaxies are consistent with those measured in the inner regions of galaxies by other studies. Furthermore, the total-mass density slopes (γtot) appear to be universal over this broad stellar mass range, with an average value of γtot =  −2.24 ±  0.05 , i.e. slightly steeper than isothermal. We compare our results to model galaxies from the Magneticum and EAGLE cosmological hydrodynamic simulations, in order to probe the mechanisms that are responsible for varying total-mass density profile slopes. The simulated-galaxy slopes are shallower than the observed values by ∼0.3–0.5, indicating that the physical processes shaping the mass distributions of galaxies in cosmological simulations are still incomplete. For galaxies with M* > 1010.7 M⊙ in the Magneticum simulations, we identify a significant anticorrelation between total-mass density profile slopes and the fraction of stellar mass formed ex situ (i.e. accreted), whereas this anticorrelation is weaker for lower stellar masses, implying that the measured total-mass density slopes for low-mass galaxies are less likely to be determined by merger activity.


Sdss-Iv Manga: The Spatially Resolved Stellar Initial Mass Function In ~400 Early-Type Galaxies, Taniya Parikh, Daniel Thomas, Claudia Maraston, Kyle B. Westfall, Daniel Goddard, Jianhui Lian, Sofia Meneses-Goytia, Amy Jones, Sam Vaughan, Brett H. Andrews, Matthew Bershady, Dmitry Bizyaev, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Niv Drory, Eric Emsellem, David R. Law, Jeffrey A. Newman, Alexandre Roman-Lopes, David Wake, Renbin Yan, Zheng Zheng Mar 2018

Sdss-Iv Manga: The Spatially Resolved Stellar Initial Mass Function In ~400 Early-Type Galaxies, Taniya Parikh, Daniel Thomas, Claudia Maraston, Kyle B. Westfall, Daniel Goddard, Jianhui Lian, Sofia Meneses-Goytia, Amy Jones, Sam Vaughan, Brett H. Andrews, Matthew Bershady, Dmitry Bizyaev, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Niv Drory, Eric Emsellem, David R. Law, Jeffrey A. Newman, Alexandre Roman-Lopes, David Wake, Renbin Yan, Zheng Zheng

Physics and Astronomy Faculty Publications

Mapping Nearby Galaxies at Apache Point Observatory provides the opportunity to make precise spatially resolved measurements of the IMF slope in galaxies owing to its unique combination of spatial resolution, wavelength coverage, and sample size. We derive radial gradients in age, element abundances, and IMF slope analysing optical and near-infrared absorption features from stacked spectra out to the half-light radius of 366 early-type galaxies with masses 9.9–10.8 log M/M. We find flat gradients in age and [α/Fe] ratio, as well as negative gradients in metallicity, consistent with the literature. We further derive significant negative gradients …


Sdss-Iv Manga: Stellar Angular Momentum Of About 2300 Galaxies: Unveiling The Bimodality Of Massive Galaxy Properties, Mark T. Graham, Michele Cappellari, Hongyu Li, Shude Mao, Matthew A. Bershady, Dmitry Bizyaev, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Niv Drory, David R. Law, Kaike Pan, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle Westfall, Renbin Yan Mar 2018

Sdss-Iv Manga: Stellar Angular Momentum Of About 2300 Galaxies: Unveiling The Bimodality Of Massive Galaxy Properties, Mark T. Graham, Michele Cappellari, Hongyu Li, Shude Mao, Matthew A. Bershady, Dmitry Bizyaev, Jonathan Brinkmann, Joel R. Brownstein, Kevin Bundy, Niv Drory, David R. Law, Kaike Pan, Daniel Thomas, David A. Wake, Anne-Marie Weijmans, Kyle Westfall, Renbin Yan

Physics and Astronomy Faculty Publications

We measure λRe⁠, a proxy for galaxy specific stellar angular momentum within one effective radius, and the ellipticity, ϵ, for about 2300 galaxies of all morphological types observed with integral field spectroscopy as part of the Mapping Nearby Galaxies at Apache Point Observatory survey, the largest such sample to date. We use the (λRe, ϵ) diagram to separate early-type galaxies into fast and slow rotators. We also visually classify each galaxy according to its optical morphology and two-dimensional stellar velocity field. Comparing these classifications to quantitative λRe measurements reveals tight …


The Sluggs Survey: Using Extended Stellar Kinematics To Disentangle The Formation Histories Of Low-Mass S0 Galaxies, Sabine Bellstedt, Duncan Forbes, Caroline Foster, Aaron Romanowsky, Jean Brodie, Nicola Pastorello, Adebusola Alabi, Alexa Villaume Jun 2017

The Sluggs Survey: Using Extended Stellar Kinematics To Disentangle The Formation Histories Of Low-Mass S0 Galaxies, Sabine Bellstedt, Duncan Forbes, Caroline Foster, Aaron Romanowsky, Jean Brodie, Nicola Pastorello, Adebusola Alabi, Alexa Villaume

Faculty Publications

We utilize the DEIMOS instrument on the Keck telescope to measure the wide-field stellar kinematics of early-type galaxies as part of the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey. In this paper, we focus on some of the lowest stellar mass lenticular galaxies within this survey, namely NGC 2549, NGC 4474, NGC 4459 and NGC 7457, performing detailed kinematic analyses out to large radial distances of ∼2–3 effective radii. For NGC 2549, we present the first analysis of data taken with the SuperSKiMS (Stellar Kinematics from Multiple Slits) technique. To better probe kinematic variations in the outskirts of the …


Galaxy And Mass Assembly (Gama) : Stellar Mass Functions By Hubble Type., Lee S. Kelvin, Simon P. Driver, Aaron S. G. Robotham, Edward N. Taylor, Alister W. Graham, Mehmet Alpaslan, Ivan K. Baldry, Steven P. Bamford, Amanda E. Bauer, Joss Bland-Hawthorn, Michael J. I. Brown, Matthew Colless, Christopher J. Conselice, Benne W. Holwerda, Andrew M. Hopkins, Maritza A. Lara-Lopez, Jochen Liske, Angel R. Lopez-Sanchez, Jonathan Loveday, Peder Norberg, Steven Phillipps, Cristina C. Popescu, Matthew Prescott, Anne E. Sansom, Richard J. Tuffs Feb 2017

Galaxy And Mass Assembly (Gama) : Stellar Mass Functions By Hubble Type., Lee S. Kelvin, Simon P. Driver, Aaron S. G. Robotham, Edward N. Taylor, Alister W. Graham, Mehmet Alpaslan, Ivan K. Baldry, Steven P. Bamford, Amanda E. Bauer, Joss Bland-Hawthorn, Michael J. I. Brown, Matthew Colless, Christopher J. Conselice, Benne W. Holwerda, Andrew M. Hopkins, Maritza A. Lara-Lopez, Jochen Liske, Angel R. Lopez-Sanchez, Jonathan Loveday, Peder Norberg, Steven Phillipps, Cristina C. Popescu, Matthew Prescott, Anne E. Sansom, Richard J. Tuffs

Benne Holwerda

We present an estimate of the galaxy stellar mass function and its division by morphological type in the local (0.025 < z < 0.06) Universe. Adopting robust morphological classifications as previously presented (Kelvin et al.) for a sample of 3727 galaxies taken from the Galaxy And Mass Assembly survey, we define a local volume and stellar mass limited sub-sample of 2711 galaxies to a lower stellar mass limit of M=109.0M⊙ M=109.0M⊙ . We confirm that the galaxy stellar mass function is well described by a double-Schechter function given by M∗=1010.64M⊙ M∗=1010.64M⊙ , α1 = −0.43, ϕ∗1=4.18dex−1Mpc−3 ϕ1∗=4.18dex−1Mpc−3 , α2 = −1.50 and …


Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget By Galaxy Type., Amanda J. Moffett, Stephen A. Ingarfield, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Rebecca Lange, Uros Mestric, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Sarah Brough, Michelle Cluver, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Peder Norberg, Edward N. Taylor Feb 2017

Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget By Galaxy Type., Amanda J. Moffett, Stephen A. Ingarfield, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Rebecca Lange, Uros Mestric, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Sarah Brough, Michelle Cluver, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Peder Norberg, Edward N. Taylor

Benne Holwerda

We report an expanded sample of visual morphological classifications from the Galaxy and Mass Assembly survey phase two, which now includes 7556 objects (previously 3727 in phase one). We define a local (z < 0.06) sample and classify galaxies into E, S0-Sa, SB0-SBa, Sab-Scd, SBab-SBcd, Sd-Irr, and ‘little blue spheroid’ types. Using these updated classifications, we derive stellar mass function fits to individual galaxy populations divided both by morphological class and more general spheroid- or disc-dominated categories with a lower mass limit of log(M*/M⊙) = 8 (one dex below earlier morphological mass function determinations). We find that all individual morphological classes …


Galaxy And Mass Assembly (Gama) : M–Re Relations Of Z = 0 Bulges, Discs And Spheroids., Rebecca Lange, Amanda J. Moffett, Simon P. Driver, Aaron S. G. Robotham, Claudia Del P. Lagos, Lee S. Kelvin, Christopher Conselice, Berta Margalef-Bentabol, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Malcolm Bremer, Sarah Brough, Michelle Cluver, Matthew Colless, Luke J. M. Davies, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Jochen Liske, Steven Phillipps, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Eelco Van Kampen, Angus H. Wright Feb 2017

Galaxy And Mass Assembly (Gama) : M–Re Relations Of Z = 0 Bulges, Discs And Spheroids., Rebecca Lange, Amanda J. Moffett, Simon P. Driver, Aaron S. G. Robotham, Claudia Del P. Lagos, Lee S. Kelvin, Christopher Conselice, Berta Margalef-Bentabol, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Malcolm Bremer, Sarah Brough, Michelle Cluver, Matthew Colless, Luke J. M. Davies, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Jochen Liske, Steven Phillipps, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Eelco Van Kampen, Angus H. Wright

Benne Holwerda

We perform automated bulge + disc decomposition on a sample of ∼7500 galaxies from the Galaxy And Mass Assembly (GAMA) survey in the redshift range of 0.002 < z < 0.06 using Structural Investigation of Galaxies via Model Analysis, a wrapper around GALFIT3. To achieve robust profile measurements, we use a novel approach of repeatedly fitting the galaxies, varying the input parameters to sample a large fraction of the input parameter space. Using this method, we reduce the catastrophic failure rate significantly and verify the confidence in the fit independently of χ2. Additionally, using the median of the final fitting values and …


Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget Of Galaxy Spheroids And Discs., Amanda J. Moffett, Rebecca Lange, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Mehmet Alpaslan, Stephen K. Andrews, Joss Bland-Hawthorn, Sarah Brough, Michelle E. Cluver, Matthew Colless, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Jochen Liske, Martin Meyer Feb 2017

Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget Of Galaxy Spheroids And Discs., Amanda J. Moffett, Rebecca Lange, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Mehmet Alpaslan, Stephen K. Andrews, Joss Bland-Hawthorn, Sarah Brough, Michelle E. Cluver, Matthew Colless, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Jochen Liske, Martin Meyer

Benne Holwerda

We build on a recent photometric decomposition analysis of 7506 Galaxy and Mass Assembly (GAMA) survey galaxies to derive stellar mass function fits to individual spheroid and disc component populations down to a lower mass limit of log(M*/M⊙) = 8. We find that the spheroid/disc mass distributions for individual galaxy morphological types are well described by single Schechter function forms. We derive estimates of the total stellar mass densities in spheroids (ρspheroid = 1.24 ± 0.49 × 108 M⊙ Mpc −3h0.7) and discs (ρdisc = 1.20 ± 0.45 × 108 M⊙ Mpc −3h0.7), which translates to approximately 50 per cent …


The Sluggs Survey: Stellar Masses And Effective Radii Of Early-Type Galaxies From Spitzer Space Telescope 3.6 Μm Imaging, Duncan Forbes, Luciana Sinpetru, Giulia Savorgnan, Aaron Romanowsky, Christopher Usher, Jean Brodie Feb 2017

The Sluggs Survey: Stellar Masses And Effective Radii Of Early-Type Galaxies From Spitzer Space Telescope 3.6 Μm Imaging, Duncan Forbes, Luciana Sinpetru, Giulia Savorgnan, Aaron Romanowsky, Christopher Usher, Jean Brodie

Faculty Publications

Galaxy starlight at 3.6 μm is an excellent tracer of stellar mass. Here we use the latest 3.6 μm imaging from the Spitzer Space Telescope to measure the total stellar mass and effective radii in a homogeneous way for a sample of galaxies from the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey. These galaxies are representative of nearby early-type galaxies in the stellar mass range of 10 < log M*/M⊙ < 11.7 and our methodology can be applied to other samples of early-type galaxies. We model each galaxy in 2D and estimate its total asymptotic magnitude from a 1D curve-of-growth. Magnitudes are converted into stellar masses using a 3.6 μm mass-to-light ratio from the latest stellar population models of Röck et al., assuming a Kroupa initial mass function. We apply a ratio based on each galaxy's mean mass-weighted stellar age within one effective radius (the mass-to-light ratio is insensitive to galaxy metallicity for the generally old stellar ages and high metallicities found in massive early-type galaxies). Our 3.6 μm stellar masses agree well with masses derived from 2.2 μm data. From the 1D surface brightness profile, we fit a single Sérsic law, excluding the very central regions. We measure the effective radius, Sérsic n parameter and effective surface brightness for each galaxy. We find that galaxy sizes derived from shallow optical imaging and the 2MASS survey tend to underestimate the true size of the largest, most massive galaxies in our sample. We adopt the 3.6 μm stellar masses and effective radii for the SLUGGS survey galaxies.


The Sluggs Survey: Revisiting The Correlation Between X-Ray Luminosity And Total Mass Of Massive Early-Type Galaxies, Duncan Forbes, Adebusola Alabi, Aaron Romanowsky, Dong-Woo Kim, Jean Brodie, Giuseppina Fabbiano Jan 2017

The Sluggs Survey: Revisiting The Correlation Between X-Ray Luminosity And Total Mass Of Massive Early-Type Galaxies, Duncan Forbes, Adebusola Alabi, Aaron Romanowsky, Dong-Woo Kim, Jean Brodie, Giuseppina Fabbiano

Faculty Publications

Here we utilize recent measures of galaxy total dynamical mass and X-ray gas luminosities (LX,Gas) for a sample of 29 massive early-type galaxies from the SLUGGS survey to probe LX, Gas–mass scaling relations. In particular, we investigate scalings with stellar mass, dynamical mass within 5 effective radii (Re) and total virial mass. We also compare these relations with predictions from Λ cold dark matter simulations. We find a strong linear relationship between LX, Gas and galaxy dynamical mass within 5Re, which is consistent with the recent cosmological simulations of Choi et al. that incorporate mechanical heating from AGN. We conclude …


Sdss-Iv Manga: Spatially Resolved Star Formation Histories In Galaxies As A Function Of Galaxy Mass And Type, D. Goddard, D. Thomas, C. Maraston, K. Westfall, J. Etherington, R. Riffel, M. D. Mallmann, Z. Zheng, M. Argudo-Fernández, J. Lian, M. Bershady, K. Bundy, N. Drory, D. Law, Renbin Yan, D. Wake, A. Weijmans, D. Bizyaev, J. Brownstein, R. R. Lane, R. Maiolino, K. Masters, M. Merrifield, C. Nitschelm, K. Pan, A. Roman-Lopes, T. Storchi-Bergmann, D. P. Schneider Dec 2016

Sdss-Iv Manga: Spatially Resolved Star Formation Histories In Galaxies As A Function Of Galaxy Mass And Type, D. Goddard, D. Thomas, C. Maraston, K. Westfall, J. Etherington, R. Riffel, M. D. Mallmann, Z. Zheng, M. Argudo-Fernández, J. Lian, M. Bershady, K. Bundy, N. Drory, D. Law, Renbin Yan, D. Wake, A. Weijmans, D. Bizyaev, J. Brownstein, R. R. Lane, R. Maiolino, K. Masters, M. Merrifield, C. Nitschelm, K. Pan, A. Roman-Lopes, T. Storchi-Bergmann, D. P. Schneider

Physics and Astronomy Faculty Publications

We study the internal gradients of stellar population properties within 1.5 Re for a representative sample of 721 galaxies, with stellar masses ranging between 109 M and 1011.5 M from the SDSS-IV MaNGA Integral-Field-Unit survey. Through the use of our full spectral fitting code firefly, we derive light- and mass-weighted stellar population properties and their radial gradients, as well as full star formation and metal enrichment histories. We also quantify the impact that different stellar population models and full spectral fitting routines have on the derived stellar population properties and the radial gradient measurements. In …


Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget Of Galaxy Spheroids And Discs., Amanda J. Moffett, Rebecca Lange, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Mehmet Alpaslan, Stephen K. Andrews, Joss Bland-Hawthorn, Sarah Brough, Michelle E. Cluver, Matthew Colless, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Jochen Liske, Martin Meyer Nov 2016

Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget Of Galaxy Spheroids And Discs., Amanda J. Moffett, Rebecca Lange, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Mehmet Alpaslan, Stephen K. Andrews, Joss Bland-Hawthorn, Sarah Brough, Michelle E. Cluver, Matthew Colless, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Jochen Liske, Martin Meyer

Faculty Scholarship

We build on a recent photometric decomposition analysis of 7506 Galaxy and Mass Assembly (GAMA) survey galaxies to derive stellar mass function fits to individual spheroid and disc component populations down to a lower mass limit of log(M*/M⊙) = 8. We find that the spheroid/disc mass distributions for individual galaxy morphological types are well described by single Schechter function forms. We derive estimates of the total stellar mass densities in spheroids (ρspheroid = 1.24 ± 0.49 × 108 M⊙ Mpc −3h0.7) and discs (ρdisc = 1.20 ± 0.45 × 108 M⊙ Mpc −3h0.7), which translates to approximately 50 …


Galaxy And Mass Assembly (Gama) : M–Re Relations Of Z = 0 Bulges, Discs And Spheroids., Rebecca Lange, Amanda J. Moffett, Simon P. Driver, Aaron S. G. Robotham, Claudia Del P. Lagos, Lee S. Kelvin, Christopher Conselice, Berta Margalef-Bentabol, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Malcolm Bremer, Sarah Brough, Michelle Cluver, Matthew Colless, Luke J. M. Davies, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Jochen Liske, Steven Phillipps, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Eelco Van Kampen, Angus H. Wright Oct 2016

Galaxy And Mass Assembly (Gama) : M–Re Relations Of Z = 0 Bulges, Discs And Spheroids., Rebecca Lange, Amanda J. Moffett, Simon P. Driver, Aaron S. G. Robotham, Claudia Del P. Lagos, Lee S. Kelvin, Christopher Conselice, Berta Margalef-Bentabol, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Malcolm Bremer, Sarah Brough, Michelle Cluver, Matthew Colless, Luke J. M. Davies, Boris Haußler, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Jochen Liske, Steven Phillipps, Cristina C. Popescu, Edward N. Taylor, Richard Tuffs, Eelco Van Kampen, Angus H. Wright

Faculty Scholarship

We perform automated bulge + disc decomposition on a sample of ∼7500 galaxies from the Galaxy And Mass Assembly (GAMA) survey in the redshift range of 0.002 < z < 0.06 using Structural Investigation of Galaxies via Model Analysis, a wrapper around GALFIT3. To achieve robust profile measurements, we use a novel approach of repeatedly fitting the galaxies, varying the input parameters to sample a large fraction of the input parameter space. Using this method, we reduce the catastrophic failure rate significantly and verify the confidence in the fit independently of χ2. Additionally, using the median of the final fitting values and the 16th and 84th percentile produces more realistic error estimates than those provided by GALFIT, which are known to be underestimated. We use the results of our decompositions to analyse the stellar mass – half-light radius relations of bulges, discs and spheroids. We further investigate the association of components with a parent disc or elliptical relation to provide definite z = 0 disc and spheroid M–Re relations. We conclude by comparing our local disc and spheroid M–Re to simulated data from EAGLE and high-redshift data from Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey-Ultra Deep Survey. We show the potential of using the M–Re relation to study galaxy evolution in both cases but caution that for a fair comparison, all data sets need to be processed and analysed in the same manner.


The Mass Discrepancy Acceleration Relation In Early-Type Galaxies: Extended Mass Profiles And The Phantom Menace To Mond, Joachim Janz, Michele Cappellari, Aaron Romanowsky, Luca Ciotti, Adebusola Alabi, Duncan Forbes Sep 2016

The Mass Discrepancy Acceleration Relation In Early-Type Galaxies: Extended Mass Profiles And The Phantom Menace To Mond, Joachim Janz, Michele Cappellari, Aaron Romanowsky, Luca Ciotti, Adebusola Alabi, Duncan Forbes

Faculty Publications

The dark matter (DM) haloes around spiral galaxies appear to conspire with their baryonic content: empirically, significant amounts of DM are inferred only below a universal characteristic acceleration scale. Moreover, the discrepancy between the baryonic and dynamical mass, which is usually interpreted as the presence of DM, follows a very tight mass discrepancy acceleration (MDA) relation. Its universality, and its tightness in spiral galaxies, poses a challenge for the DM interpretation and was used to argue in favour of MOdified Newtonian Dynamics (MOND). Here, we test whether or not this applies to early-type galaxies. We use the dynamical models of …


The Sluggs Survey*: Exploring The Globular Cluster Systems Of The Leo Ii Group And Their Global Relationships, Sreeja Kartha, Duncan Forbes, Adebusola Alabi, Jean Brodie, Aaron Romanowsky, Jay Strader, Lee Spitler, Zachary Jennings, Joel Roediger May 2016

The Sluggs Survey*: Exploring The Globular Cluster Systems Of The Leo Ii Group And Their Global Relationships, Sreeja Kartha, Duncan Forbes, Adebusola Alabi, Jean Brodie, Aaron Romanowsky, Jay Strader, Lee Spitler, Zachary Jennings, Joel Roediger

Faculty Publications

We present an investigation of the globular cluster (GC) systems of NGC 3607 and NGC 3608 as part of the ongoing SLUGGS (SAGES Legacy Unifying Globulars and GalaxieS) survey. We use wide-field imaging data from the Subaru telescope in the g, r and i filters to analyse the radial density, colour and azimuthal distributions of both GC systems. With the complementary kinematic data obtained from the Keck II telescope, we measure the radial velocities of a total of 81 GCs. Our results show that the GC systems of NGC 3607 and NGC 3608 have a detectable spatial extent of ∼15 …


The Sluggs Survey: Globular Clusters And The Dark Matter Content Of Early-Type Galaxies, Duncan Forbes, Adebusola Alabi, Aaron Romanowsky, Jean Brodie, Jay Strader, Christopher Usher, Vincenzo Pota May 2016

The Sluggs Survey: Globular Clusters And The Dark Matter Content Of Early-Type Galaxies, Duncan Forbes, Adebusola Alabi, Aaron Romanowsky, Jean Brodie, Jay Strader, Christopher Usher, Vincenzo Pota

Faculty Publications

No abstract provided.


Erratum: The Sluggs Survey: The Globular Cluster Systems Of Three Early-Type Galaxies Using Wide-Field Imaging, Sreeja Kartha, Duncan Forbes, Lee Spitler, Aaron Romanowsky, Jacob Arnold, Jean Brodie Apr 2016

Erratum: The Sluggs Survey: The Globular Cluster Systems Of Three Early-Type Galaxies Using Wide-Field Imaging, Sreeja Kartha, Duncan Forbes, Lee Spitler, Aaron Romanowsky, Jacob Arnold, Jean Brodie

Faculty Publications

The paper ‘The SLUGGS survey: the globular cluster systems of three early-type galaxies using wide-field imaging’ was published in Monthly Notices of the Royal Astronomical Society, 437, 273 – 292 (2014).


The Sluggs Survey: The Assembly Histories Of Individual Early-Type Galaxies, Duncan Forbes, Aaron Romanowsky, Nicola Pastorello, Caroline Foster, Jean Brodie, Jay Strader, Christopher Usher, Vincenzo Pota Apr 2016

The Sluggs Survey: The Assembly Histories Of Individual Early-Type Galaxies, Duncan Forbes, Aaron Romanowsky, Nicola Pastorello, Caroline Foster, Jean Brodie, Jay Strader, Christopher Usher, Vincenzo Pota

Faculty Publications

Early-type (E and S0) galaxies may have assembled via a variety of different evolutionary pathways. Here, we investigate these pathways by comparing the stellar kinematic properties of 24 early-type galaxies from the SAGES Legacy Unifying Globulars and GalaxieS (SLUGGS) survey with the hydrodynamical simulations of Naab et al. In particular, we use the kinematics of starlight up to 4 effective radii (Re) as diagnostics of galaxy inner and outer regions, and assign each galaxy to one of six Naab et al. assembly classes. The majority of our galaxies (14/24) have kinematic characteristics that indicate an assembly history dominated by gradual …


Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget By Galaxy Type., Amanda J. Moffett, Stephen A. Ingarfield, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Rebecca Lange, Uros Mestric, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Sarah Brough, Michelle Cluver, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Peder Norberg, Edward N. Taylor Apr 2016

Galaxy And Mass Assembly (Gama) : The Stellar Mass Budget By Galaxy Type., Amanda J. Moffett, Stephen A. Ingarfield, Simon P. Driver, Aaron S. G. Robotham, Lee S. Kelvin, Rebecca Lange, Uros Mestric, Mehmet Alpaslan, Ivan K. Baldry, Joss Bland-Hawthorn, Sarah Brough, Michelle Cluver, Luke J. M. Davies, Benne W. Holwerda, Andrew M. Hopkins, Prajwal R. Kafle, Rebecca Kennedy, Peder Norberg, Edward N. Taylor

Faculty Scholarship

We report an expanded sample of visual morphological classifications from the Galaxy and Mass Assembly survey phase two, which now includes 7556 objects (previously 3727 in phase one). We define a local (z < 0.06) sample and classify galaxies into E, S0-Sa, SB0-SBa, Sab-Scd, SBab-SBcd, Sd-Irr, and ‘little blue spheroid’ types. Using these updated classifications, we derive stellar mass function fits to individual galaxy populations divided both by morphological class and more general spheroid- or disc-dominated categories with a lower mass limit of log(M*/M⊙) = 8 (one dex below earlier morphological mass function determinations). We find that all individual morphological classes and the combined spheroid-/bulge-dominated classes are well described by single Schechter stellar mass function forms. We find that the total stellar mass densities for individual galaxy populations and for the entire galaxy population are bounded within our stellar mass limits and derive an estimated total stellar mass …


The Sluggs Survey: Chromodynamical Modelling Of The Lenticular Galaxy Ngc 1023, Arianna Cortesi, Ana Chies-Santos, Vincenzo Pota, Caroline Foster, Lodovico Coccato, Claudia Mendes De Oliveira, Duncan Forbes, Michael Merrifield, Steven Bamford, Aaron Romanowsky, Jean Brodie, Sreeja Kartha, Adebusola Alabi, Robert Proctor, Andres Almeida Mar 2016

The Sluggs Survey: Chromodynamical Modelling Of The Lenticular Galaxy Ngc 1023, Arianna Cortesi, Ana Chies-Santos, Vincenzo Pota, Caroline Foster, Lodovico Coccato, Claudia Mendes De Oliveira, Duncan Forbes, Michael Merrifield, Steven Bamford, Aaron Romanowsky, Jean Brodie, Sreeja Kartha, Adebusola Alabi, Robert Proctor, Andres Almeida

Faculty Publications

Globular clusters (GCs) can be considered discrete, long-lived, dynamical tracers that retain crucial information about the assembly history of their parent galaxy. In this paper, we present a new catalogue of GC velocities and colours for the lenticular galaxy NGC 1023, we study their kinematics and spatial distribution, in comparison with the underlying stellar kinematics and surface brightness profile, and we test a new method for studying GC properties. Specifically, we decompose the galaxy light into its spheroid (assumed to represent the bulge+halo components) and disc components and use it to assign to each GC a probability of belonging to …


Vegas: A Vst Early-Type Galaxy Survey: I. Presentation, Wide-Field Surface Photometry, And Substructures In Ngc 4472, Massimo Capaccioli, Marilena Spavone, Aniello Grado, Enrichetta Iodice, Luca Limatola, Nicola Napolitano, Michele Cantiello, Maurizio Paolillo, Aaron Romanowsky, Duncan Forbes, Thomas Puzia, Gabriella Raimondo, Pietro Schipani Sep 2015

Vegas: A Vst Early-Type Galaxy Survey: I. Presentation, Wide-Field Surface Photometry, And Substructures In Ngc 4472, Massimo Capaccioli, Marilena Spavone, Aniello Grado, Enrichetta Iodice, Luca Limatola, Nicola Napolitano, Michele Cantiello, Maurizio Paolillo, Aaron Romanowsky, Duncan Forbes, Thomas Puzia, Gabriella Raimondo, Pietro Schipani

Faculty Publications

Context. We present the VST Early-type GAlaxy Survey (VEGAS), which is designed to obtain deep multiband photometry in g,r,i, of about one hundred nearby galaxies down to 27.3, 26.8, and 26 mag/arcsec2 respectively, using the ESO facility VST/OmegaCAM.Aims. The goals of the survey are 1) to map the light distribution up to ten effective radii, re; 2) to trace color gradients and surface brightness fluctuation gradients out to a few re for stellar population characterization; and 3) to obtain a full census of the satellite systems (globular clusters and dwarf galaxies) out to 20% of the galaxy virial radius. The …


Vimos Mosaic Integral-Field Spectroscopy Of The Bulge And Disc Of The Early-Type Galaxy Ngc 4697, C. Spiniello, N. Napolitano, L. Coccato, V. Pota, Aaron Romanowsky, C. Tortora, G. Covone, M. Capaccioli Sep 2015

Vimos Mosaic Integral-Field Spectroscopy Of The Bulge And Disc Of The Early-Type Galaxy Ngc 4697, C. Spiniello, N. Napolitano, L. Coccato, V. Pota, Aaron Romanowsky, C. Tortora, G. Covone, M. Capaccioli

Faculty Publications

No abstract provided.